In the Field: JVC GY–HM100
Posted Jan 29, 2010

JVC GY-HM100Unlike other reviews of mine, I approached this one by taking the questions and thoughts of fellow videographers on camera issues and choices and applying them to JVC’s GY-HM100U (Figure 1, right). The HM100U, introduced in mid-2009, is generally perceived as the small camera in JVC’s ProHD line, which was established with the highly innovative and groundbreaking shouldermount GY-HD100U in 2005 and continues today with the HM250U and the HM700U. Once it was in my hands, I immediately set out to use the HM100U as a pro camcorder, and I documented my findings. Here’s how it measured up against similarly positioned prosumer HDV cameras.

Like other models in the ProHD line, the HM100U has an AE ± (plus or minus) button right above the rear rocker adjustment that enables you to tick the camera exposure up or down in the middle of a shot (Figure 2, below). With two taps (and no menus), I can compensate when the camera tries to open up on a wall of dark tuxes and when it overexposes faces.

The JVC HM100's AE± button

The zebra has a nice feature: You can adjust the bottom and top luminance values that activate it. For instance, you may want the zebra to focus on skin tones, but skin tones vary greatly with lighter-skinned or darker-skinned people. You can set the bottom value to 50% and the top value to 70%, or you can set either to any value from 0 to more than 100 in 5% increments. If you were so inclined, you could use this zebra to indicate crushed black levels.

With the ability to manually control the gain, shutter, and iris, you can freeze the current exposure and adjust it as needed in the middle of a shot. Unfortunately, the iris steps are clearly visible in the video. I’d like to see the multifunction focus ring offer smooth iris adjustment instead of zoom; there are already two other ways to control the zoom on the camera.

The gain adjustment is up front with the lens. But it really belongs with the iris and shutter settings so that all three settings that control exposure are together and easily adjustable without having to roam around the camera. The gain has low, medium, and high settings. You have to use one of those for auto, unless you never want access to auto gain levels. Then, you can set the other two to values between 3dB and 18dB. I find auto very useful for reception floors where light levels vary dramatically.

There is a menu for mic-level settings that is identical to the menu in the JVC GZ-HD40US high-end consumer camcorder—I used this camera on a trip to Alaska, as described in my November 2008 In the Field article,  “JVC GZ-HD40U and Canon Vixia HF-10A.” The audio can be adjusted within the following range: –2, –1, 0, +1, +2 (Figure 3, below). What this means in reality is unknown. You expect a scale of 0–10 here, where 0 is no audio passing through and 10 is full volume, settings that are found only on the XLR adapter handle.

HM100U menu for mic-level settings

When in color bars, the camera doesn’t offer tone. If you want to use the color bars to adjust the LCD screen, you’re out of luck. The instant you touch the Menu button to get to the brightness settings, the camera drops the color bars and reverts back to the live video feed from the lens. When you’re in the brightness adjustment, you can’t toggle through color bars.

The gamma is user-configurable, but the overall white and black points are not affected. I personally prefer to capture without any effects and then add them in post, unless there’s a need to turn the footage around immediately and shoot with a “look”; this will help avoid any postprocessing time. While playing around in the gamma settings, you can’t use the zoom to adjust your shot, so you’ll need to exit the menu, frame your shot—such as to a dark area—and then adjust your settings.

Some of the menus are long, so it’s handy that they wrap around and start over from the top, as opposed to forcing you to go back up from the bottom. However, the scroll indicator on the right side of the screen is not very visible, and there’s plenty of room in the 16:9 frame that JVC could have used to enlarge it.

One very confusing aspect to the camcorder’s settings is in the two menus that control the HD settings. Choosing System Select elicits a pop-up menu that lets you choose between U.S. or European (60/50 Hz) systems as well as 1080- and 720-pixel frame sizes. Selecting Rec Mode opens a pop-up that lets you pick between 1920/60i and 1920/30p.

But the issue here is that Rec Mode doesn’t use the same standard numbers that the System Select menu uses. Changes in the System Select options cause the camera to reboot. A third menu lets you choose between an MOV file format (QuickTime) and an XDCAM EX’s MP4 file format and folder structure.

When you have the camera set to MP4, the camera format part of the display is orange. When you change the setting to QuickTime, that part of the display changes to blue. This provides a “quick-glance” confirmation of your recording format since there is no on-screen MP4/MOV indicator.

For a tiny handheld camcorder, the HM100U’s optical image stabilizer (OIS) does a pretty good job. But the camera’s lack of mass means you’ll end up with “floaty-cam” footage when you try to shoot with the lens zoomed all the way in. There’s just no way to hold it steady enough in your hands alone. The rest of JVC’s ProHD line, by contrast, offers the on-shoulder ergonomics that ensure steadier footage.

Also, I have seen the OIS exhibit what I call “mosquitoes” flying around tiny chandelier and wall lights. These are actually internal reflections of the point-source lights in the OIS system. The reflections move with the actions of the OIS compensation lenses, which are clearly visible behind a flat front glass on the lens. The HM100U lacks enough optical coatings to hide this.

The consumer GZ-HD40’s digital image stabilizer (DIS) would not have these artifacts, but, generally, DIS does not perform as well as OIS. The macro capabilities are quite good, enabling you to focus down to an inch or so—definitely to the point to where the lens itself blocks the light on the subject. The zoom rocker looks nice and big and has a nice amount of swing. But aside from an acceptable slow zoom, there isn’t a really slow crawl, and the steps between the zoom speeds are quite noticeable.

When shooting in 24p, you can adjust your shutter to 1/24 to get more light than you would get shooting 1/60 video. But you get the judder that is typical of a slower shutter and is more visible than 30p judder. You can step up to a 1/48 shutter, but that just reduces the light captured and image blur at the 24p setting; it does not reduce judder caused by the slow frame rate. The camera always defaults back to 1/48 when you choose the 24p setting.

The HM100U sports two SD card slots. If you’re rolling on card A and there’s nothing in slot B, tapping the A/B button does nothing. So you don’t have to worry about accidental button presses there.
Hitting the record button immediately starts video capture. Hitting it a second time stops capture. The camera takes an additional 2–3 seconds to do a little data housekeeping, and the data activity light keeps blinking. You can’t immediately jump right back into recording or enter the menu while this data housekeeping is going on.

The HM100U requires a class 6 SDHC card. I tried to capture with a class 4 card, but I got a warning message on the camcorder—it would not even attempt to use it.

The HM100U’s internal wind cut filter can be manually assigned to the internal mics or to either of the two XLR mic inputs. Each can be individually toggled on or off. This is a pretty nice feature. You can set the audio reference levels to -20 or -12. But in my tests, leaving the audio in auto and adjusting the settings made no difference to the audio levels I viewed on the camera’s meter or in the files on the computer.

The audio monitor lets you mix the audio from both channels in both ears, or it lets you hear discrete audio from channel 1 and 2 in the left and right ears, respectively. If you’re listening to the camera audio with only one ear but need to hear both mics, the ability to pick mixer audio is very useful.

The top-mounted mic worked well enough for casual use, but for any serious use, you’ll want to add the XLR jack adaptor. This gives you the ability to accept mic- or line-level, balanced audio; send one input to both channels; and set either to auto or manual level. The level dials are very conveniently placed, though a little small for my tastes. There’s no reason they had to be designed from scratch to be so tiny.


I took a few still images while shooting video, taking advantage of a nice feature available on new video cameras that their video-capable DSLR cousins don’t have: the ability to seamlessly pull a frame out of the video stream and save it to the flash media in its own folder. A careful check of the still image shows that it is a straight pull from the video—gamma and colorimitry are identical. It’s the same pixel size as the video, whether the still is taken while shooting video or not.

Even if you’re not shooting video, the stills are restricted to the video resolution settings. At 1920x1080, that’s a 2 megapixel photo.

The HM100U captures great-looking video in good light. Of course, any consumer cam can do that. When I tested the HM100U at an actual event reception, however, the 18dB gain was no match for my 5-year-old Sony FX1, which is also a CCD-based model. The JVC was at least two stops darker (Figure 4, below—the Sony is on top and the JVC is on the bottom). That said, the 18dB setting on the JVC was very clean.

Rop: The HM100U at 18db gain; bottom: the Sony FX1 at 18dB gain. The JVC is at least 2 stops darker.

The HM100U also has a “LoLux” mode that, when enabled, removes gain and shutter from your control. The LoLux image (on the right in Figure 5, below) is brighter than 18dB on my Sony (on the right in Figure 5, below), but the noise makes the image nearly unusable. High-grain and even additional nongrain noise blanket the image.

Left: The HM100 in LoLux mode; right: the FX1 at 18dB gain.

The HM100U’s focus assist—another feature borrowed form the rest of the ProHD line—makes manual focusing really pop on the screen. The camera lets you know, visually, the objects that have sharp edges by coloring the edges. There’s no doubt in my mind that this version of “peaking” is the best idea for limited-resolution LCD screens. It’s still easy to manually track focus on whatever you want, amid a busy visual frame.

As mentioned earlier, the HM100U shoots in two formats: the MPEG-4-based Sony XDCAM EX format, which generates MP4 files, and MPEG-2-based MOV files. As most readers know, MPEG-4 is a more efficient codec than MPEG-2 and should deliver better images at comparable data rates. The trick, though, is getting your software to handle it. Some applications handle it natively; others need assistance, and Sony offers this for free (as it should). To get help from Sony, just search for XDCAM at sony-software.aspx, or you can get it courtesy of Sony Canada at

If your video consists of easy-to-compress stuff—talking heads, etc.—then I’d recommend the drag-and-drop simplicity of the MPEG-2 MOV files, given the difficulties I had importing the XDCAM EX MP4 files. Maybe in a year or so, they’ll cram all the metadata into video file “packages” to avoid all this special import software and untouchable, unrenamable folder structure business we have to work around now.

The grip on the HM100U feels like it’s sloped forward slightly, so at eye level, it feels fine. But at any lower angle, like chest height or waist height, I long for the more-comfortable swivel grip of JVC’s first HDV camcorder, the GR-HD1.

The grip is also too short, vertically, or the strap is too low and thin. There is nothing on the camera pressing against the base of your palm to keep the camera vertical in one hand. You either have to use your left hand or use your fingers from your right hand to pull across the top of the camera to keep it vertical.

The balance from front to back is OK overall, but adding the XLR adapter handle and the included short shotgun mic pulls the balance far forward. Even with the “big” battery on the back of the camcorder, there is little to pull the weight back to center with the XLR jacks and mic attached.

The Full Auto button is poorly located smack-dab in the middle of all the other buttons on the lens. But JVC has thankfully addressed the issue by requiring two pushes on the button to change between auto and manual modes. One errant click merely brings up a display to tell you what mode you are currently in.

After hitting the menu button on the body of the camera, you naturally go to the nearest navigation item, which is the vertical rocker on the back of the camera. However, this does nothing in the menus. Instead, you have to go all the way to the outer edge of the LCD and use the Telephoto/Wide joystick to navigate through the menu system.

The camera informed me that a charged 16wH battery would last about 100 minutes. I know from experience that zooming, continued handheld operation where the OIS system is constantly working, and autofocus will all reduce that actual run time per battery. The little battery icon changed color from green to yellow when it got down to two ticks instead of three. Why the numerical run time left on a battery isn’t available on the main display is something I just can’t fathom.

The little joystick on the outer edge of the LCD screen is the unlabeled deck control system. This is how you fast-forward, rewind, and navigate between clips. Yes, this is covered in the manual, but there’s no silk-screened labeling on the camcorder to indicate this.

The LCD display is far, far better than the electronic viewfinder, which looks to be a 4:3 display with letterboxed video in the middle of it. Even worse is the plastic casing for the eyepiece. It can mask off part of the viewfinder so that if your eye isn’t properly aligned, you can’t see part of the display in the viewfinder.

That said, the swing-out LCD screen suffers from a vertically restrictive usable viewing angle. If you move your head just a few degrees up or down, the image goes from looking good to being washed out. I almost wish they had designed the LCD sideways so that the vertical viewing angle was great but was restricted horizontally—or used a better LCD with a genuinely wider viewing angle.

The vertical rocker on the back of the camera that is used to adjust the iris and shutter is functionally backward. You push it up to decrease the numerical value of either setting. You push it down to go from f2 to 2.2, 2.5, etc. On every other camera I’ve used, “up” means higher numbers. And this is how it works on the JVC’s AE ±, which is right there with the iris and shutter adjustments.

The previous note about the rocker switch on the back of the camera increasing or decreasing values in an inconsistent manner is indicative of the split personality of this camcorder, which has some pro features borrowed from other models in the ProHD line but, in other respects, seems like a miscategorized consumer model. Another key example of this is the menu system itself, where adjusting some menu items takes you right out of the menu system altogether, forcing you to start over for each little tweak, and other menu items can be adjusted without leaving the menus.

Some menus toggle a complete submenu system, but most elicit what would be called “pop-up” menus that appear over the previous menu system. It’s clear that certain features were grafted onto a formerly unified system. And this is where the HM100U resides. It’s a consumer camera at heart—a decent one too. Yet it’s been given XDCAM EX 35Mbps recording; worldwide HD standards, including 24p; XLR jacks; two SD card slots; and more features that are straight out of the ProHD repertoire.

I’d hate for dedicated users of JVC’s ProHD products to come to this camcorder expecting the same great level of integration and performance as the rest of the ProHD line. Even though the HM100U is found online on JVC’s ProHD page, the HM100U is called a “compact hand-held 3-CCD camcorder,” which is exactly what it is.

XDCAM recording and inclusion on JVC’s ProHD camcorder comparison page serve only to confuse potential buyers and make them expect more out of the HM100U than it can deliver. Marketed correctly, this is a fine consumer camcorder, but it’s not ProHD.

Anthony Burokas ( runs IEBA Communications in Frisco, Texas.